Landing gear



Feb. 1, 1949.

w. HUNTER LANDING GEAR Filed Dec. 3, 1945 Biz 27km.

.providea compact'wheel and driving mecha- Patented Feb. 1, 1949 PATENT OFFlCE 7 "LANHINGGEAE -WillsongH;Hunter, Lakewoodp-Ohio, assignor to Ft Goodrich Company, New York, N. Y,

a corporationof New .rork a osition December 3, 1943, Serial No. 512,720

' 1 3- Claims.

I This invention relates to landing gear for aircraft and especially.to-power-drivenwheel asseznblies for aircraft. .The principal. objects of the invention are to useful fortaxii-ng the. aircraft. and iorrotating the,wheelspriortolanding, to provide for the incorporation.therewith of a brake, to incorporate the-above-stated features inwa compact dual wheel assemblmtoprovide 'for longer life of the tires on the whecls -and to provideconvenience ofn'ianufacture, assembly, and .rnaintenance, and

effectiveness 7 ,of operation.

These and other objects and advantages willbc apparentufrom the following description, reference being had to the. accompanying drawings which form a part of this specification and in shown in the drawings, an airplane I is provided with retractable landing gear of the tricycle type comprising a wheel structure II at the front of the fuselage and spaced-apart dual wheel structures I2 at the wings. The dual-wheel structures include supporting struts-l3 and I5; thestruts It may have telescopic mechanisms (not shown) for absorbing shocks during landing and taxiing operations- Each wheel structure l2 may be retracted and positioned within the. space at 55 in engine mounting structure 16 during flight. The dual wheel structure l2 includes a power-driven wheel assembly l1 having a differential housing l8 comprisinga banjo. member Illa and side plates I82) and I 80 secured to such banjo'member 18a as by suitable .circumferentially spaced-apart screw fasteners IS. The strut I3 is pivotally attached at I351. to such housing 18 as-shown especially in Fig. 3, and the strut M may be integral with'the banjo member Illa.

Since the wheel assembly 11 is constructionally symmetrical about the strut I4, only one side of thedual construction-'needbe described spec-in cally... For driving the dual wheel assembly H, a

tubular drive shaft 29. from a suitable source of nil) :worm rotatably mounted on bail beariends-of. axles or shafts 2? and m 29 having struts 2% which project t.

power, such, for example, as an electric or fluidoperatednmotcr which may be dispos d in the with a splined in the differential housing It having a prcte Thsworm 23 is in driving engagement with a we gear 2 A differential driving mechanism for .36 wheels includes the worm and the worm gear-2 s, which gear is rotatably mounted at its side .fianges 24 a on. spaced-apart ball 25 within and supported by the housing and includes beveled side gears 25 mounted on splined ng wi i by spider h tering apertures in the rim of the worrn gear as shown especially in Figs. 2 and 3.

pinion or, spider gears 28 supportv 1 ,The-shaft 2'1 is. supported adiacent its splined end by a ball bearing 3% and at the opposite end byraneedle bearing 33! mounted within a sleeve or shafthousing 3? and these bearings are positioned against shoulders in such housing The shaft housing 3'2 and an annular channeled torque frame 33 are attached to and supported by the diiferential housing it? by suitable sClcW fasteners as,

by this attachment at both sides of the 1andi gear unit the laterally projecting shaft houslugs or sleeves 32 together with the housing is and the strut structure I3, 14 as seen from the front constitute aninverted T-support with the strut structure l3, I4 constituting the stern of the T and the sole supporting connection of the landing gear to the aircraft- A wheel hub 35 is rotatably mounted .on the sleeve or shaft housing 32 by snacedrapart roller bearings 36 and seated against shoulders in the hub 35. The bearing 3'5 isv positioned and protected against grease leak.- age and the entrance of dirt by a suitable retainer and sealing. member 38. For retaining wheel hub 35 on the shaft housing 32 positioning the, roller bearing 3% and the needle bearing 3|, a nut 39 which may be of the locking type, threadedly engages the end of the axle houstending annular web or flange portion 41 to which portion an annular rim 52 may be mounted as by suitable circumfcrentially spaced-apart screw fats teners 43; The rim is adapted to receive a pneumatic tire comprising a casing M and an inner tube 45 with inflating valve-extends through ,an aperture in the rho 42. A circumferentially split ring ll seated in a recess holds a demountable rim flange 48 on the rim 2 for facilitating detachably mounting the pneumatic tire. For protecting the end of the wheel assembly ii and for promoting streamline flow of air at such end, a wheel cap 39 including sp-acedapart spring clips 59 may be detachably secured to the rim 52.

Braking of the wheel assembly i! may be accomplished by a fiuid-operated brake structure disposed. desirably adjacent the differential housing I6 and between the wheel hub 35 and the rim 32. The brake structure comprises an annularly flanged brake drum in overlying spaced-apart relation with the torque frame 33, the drum being attached as by screw fasteners to the flange portion M of the wheel hub 35 for rotation with the wheel. Friction blocks 52 are disposed within the circumferential channel of the torque frame 33 adjacent the brake drum 5| for engaging the inner surface thereof. An annular inflatable tube 53 is mounted between the friction blocks 52 and the torque frame 33 for moving the blocks into sliding contact with the brake drum 5! upon inflation of the tube by fluid under pressure admitted through an inlet connector 54 in communication therewith and with a suitable source of fluid. Associated retractor springs (not shown) may be included for facilitating the return of the friction blocks to their released position within the channel of the torque frame 33. A guard ring 55 may be attached as by screw fasteners 55 to the torque frame as shown especially in Fig. 2, for preventing the entrance of foreign material thereby maintaining the effective operation of the brake structure.

In some cases it may be desirable to provide free rotation of both wheels relative to the driving mechanism as in the case of a landing with the power to the driving mechanism being cut.

off. This may be accomplished by the arrangement shown especially in Figs. 2 and 4, utilizing an over-running clutch or free-wheeling structure 5'5 for each wheel. The free-wheeling structure 56 may comprise an outer casing 51, which casing may be an integral flange portion at the end of the wheel hub 35, and an inner hub or cam 53 integral with the end of the axle or shaft 2?. Between the outer casing and the inner'cam is a series of hardened steel rollers or balls 59 which run in slightly tapered race-ways 60. A cover plate 6| for retaining the balls 59 in position and for preventing the entrance of foreign material may be attached to the outer casing 51 as by screw fasteners 62. When power is applied through the axle 21 to the inner cam 58, the balls 59 frictionally contact the outer casing 51 rotating with the wheel hub 35. When no power is delivered to the axle, the rotation of the wheel by virtue of its contact with the ground rotates the outer casing breaking the driving connection between the wheel and the shaft, thereby permitting the wheel to rotate freely relative to the shaft 21.

For taxiing the aircraft, or for rotating the wheels prior to landing, power is supplied through the drive shaft 20 to the worm 23 thus rotating the worm gear 24, which rotation drives the shaft 27 through the differential drive mechanism. The shaft in turn transmits rotative power through the free-wheeling structure to the wheel hub 35, thereby causing the wheelto rotate at the desired speed. Braking is accomplished by admitting fluid under pressure to the inflatable tube 53 thus engaging the friction blocks 52 with the drum 5|, thereby retarding or preventing r0- tation of the wheels.

The invention thus provides for effectively driving the wheels of the aircraft, facilitating taxiing such aircraft without using the propellers, and also provides for rotating. the wheels prior to landing, which rotation may be at a speed equal to or substantially equal to the ground speed of the aircraft, thereby establishing rolling contact at impact and reducing wear and shock. Also, maneuverability of the aircraft on the ground is 'promoted.

Variations may be made without departing from the scope of the invention as it is defined in the following claims.

I claim:

1. An aircraft dual wheel landing gear comprising a pair of landing wheels in close side-byside relation and including axially aligned hubs, a supporting strut structure extending generally vertically between said wheels in the landing position, a housing at the lower end of the strut structure between said wheels and a pair of supporting tubular members united with and projecting laterally from said housing and constituting with said strut structure and housing a T-shaped support, said hubs being positioned in telescopic relation on said tubular members, bearings between each hub and tubular member at spacedapart positions along the member, driving means in said housing and extending through said tubular members to the outer ends thereof, means at said outer ends for connecting said driving means with the respective wheel, and brake structures individual to said wheels and disposed between said housing and the respective wheel, each brake structure comprising brake elements one of which is mounted on said T-shaped support at said housing and the other brake element is mounted on the adjacent wheel.

2. An aircraft dual wheel landing gear comprising a pair of landing wheels in close side-byside relation and including axially aligned hubs, a supporting strut structure extending generally vertically between said wheels the landing position, a housing at the lower end of the strut struc ture between said wheels and a pair of supporting tubular members united with and projecting laterally'from said housing and constituting with said strut structure and housing a T-shaped sup port, said hubs being positioned in telescopic relation on said tubular members and terminating at their inner ends short of said housing providing spaces between the hubs and housing, rollingcontact bearings between each hub and tubular member at spaced-apart positions along the member, driving means in said housing and extending through said tubular members to the outer ends thereof, over-running clutch means at said outer ends for free-wheeling connection of said driving means with the respective wheel, and brake structures individual tosaid wheels and disposed in said spaces between said housing and said hub, each brake structure comprising brake elements one of which is mounted on said hone ing and the other brake element is mounted on the adjacent hub at said inner end thereof.

3. An aircraft dual wheel landing gear comprising a pair of landing wheels in close side-byside relation and including axially aligned hubs, a supporting strut structure extending generally vertically between said wheels in the landing position, a housing at the lower end of the strut structure and a pair of supporting tubular members united with and projecting laterally from said housing and constituting with said strut structure and housing a T-shaped support, said hubs being positioned in telescopic relation on said tubular members and having an end overhanging the outer ends of the tubular members and terminating at their inner ends short of said housing providing spaces between the hubs and housing, rolling-contact bearings between each hub and tubular member at spaced-apart positions along the member, driving means in said housing including drive shafts individual to said wheels extending through said tubular members and beyond said outer ends thereof, over-running clutch means at said outer ends for free-wheeling connection of said shafts with the overhanging ends of said hubs, and brake structures individual to said wheels and disposed in said spaces between said housing and said inner ends of said hubs, each brake structure comprising brake elements one of which is mounted on said housing and the other brake element is mounted on the adjacent hub at said inner end thereof.

WILLSON H. H ER.

REFERENCES CITED The following references are of record in the of this patent:

UNITED STATES PATENTS Number Name Date 1,092,494 Lindsay Apr. 7, 1914 1,187,710 Church June 20, 1916 1,317,910 Distefano Oct. 7, 1919 1,524,352 Gephart Jan. 27, 1925 1,708,249 Abel Apr. 9, 1929 1,812,143 Dugan June 30, 1931 2,030,548 Smeets Feb. 11, 1936 2,287,491 Wolverton et a1. June 23, 1942 2,298,523 Webster Oct. 13, 1942 2,401,364 Mercier June 4, 1946 FOREIGN PATENTS Number Country Date 143,591 Great Britain May 28, 1920 151,635 Great Britain Sept. 25, 1920 

